Stdlib: tempnam() prefix length (64) + invalid dir fallback notices parity

[PurHur]

Category

stdlib

Problem

tempnam() has several php-src-specific behaviors that should match Zend:

• Prefix is truncated to a max length (64) in php-src
• Invalid/non-existing $directory falls back to system temp dir and emits a Notice
• Type validation and null-byte rejection should match Zend error/exception types

php-src reference

• Core temp file creation: main/php_open_temporary_file.c
• tempnam() implementation: ext/standard/file.c
• Tests:
  • ext/standard/tests/file/tempnam_variation9.phpt (prefix max length)
  • ext/standard/tests/file/tempnam_variation7-win32.phpt (invalid/non-existing dir fallback behavior)
  • ext/standard/tests/file/tempnam_variation4.phpt (null byte handling)

Repro

Save as repro_tempnam_prefix_fallback.php:

<?php

$dir = __DIR__ . '/tempnam-test';
@mkdir($dir);

$prefix = 'begin_' . str_repeat('x', 300) . '_end';
$f = tempnam($dir, $prefix);

echo "basename-len=", strlen(basename($f)), "\n";
unlink($f);

// Invalid dir: should fall back to sys_get_temp_dir() and emit a Notice.
$f2 = tempnam("/definitely/does/not/exist", "pfx");
echo "fallback-dir=", realpath(dirname($f2)) === realpath(sys_get_temp_dir()) ? 'yes' : 'no', "\n";
unlink($f2);

Run in Docker:

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
php repro_tempnam_prefix_fallback.php
./phpc run repro_tempnam_prefix_fallback.php
# Today: prefix length and/or fallback notice behavior mismatch
'

Scope (this repo)

• ext/standard temp file logic (prefix truncation, path validation)
• VM error reporting: Notice emission parity for fallback
• Compliance PHPT(s) ported from php-src (focus on prefix length + invalid dir fallback)

Done when

• repro_tempnam_prefix_fallback.php matches Zend under ./phpc run
• Port the relevant php-src PHPT expectations (prefix length + fallback notice/dir)
• Null-byte rejection matches php-src (TypeError/ValueError + message close enough)
• ./script/ci-fast.sh --filter VMTest passes for the added tests

[PurHur]

Implementation-ready addendum

Repro commands (both engines)

# This compiler
./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && php bin/vm.php repro.php'

# Zend reference
php repro.php

Done when

• Matches php-src PHPT expectations for prefix truncation (max 64) (see ext/standard/tests/file/tempnam_variation9.phpt).
• Invalid/non-existing $directory emits the same Notice text/classification and falls back to sys_get_temp_dir() (see ext/standard/tests/file/tempnam_variation7-win32.phpt + linux variants).
• Null byte and type validation match php-src (ext/standard/file.c), including ValueError/TypeError vs warning behavior for targeted PHP version.
• Add/port compliance cases under test/compliance/cases/stdlib/tempnam_*.phpt covering:
  • prefix truncation
  • invalid dir fallback + notice
  • null-byte rejection

Scope pointers (this repo)

• Likely entry: ext/standard/tempnam.php (if present) + ext/standard/Module.php registration
• Any shared temp helpers in ext/standard/file_* builtins

[PurHur]

claim: PHP Compiler STD Lib — starting this run

[PurHur]

claim: PHP Compiler STD Lib — starting this run

[PurHur]

Merged via #8014

Verification (Docker):

• php bin/vm.php test/repro/maintainer_tempnam_4401.php — prefix len 69, fallback-dir yes, null-byte ValueError
• php bin/jit.php test/repro/maintainer_tempnam_4401.php — same
• php bin/compile.php -l test/repro/maintainer_tempnam_4401.php — OK
• vendor/bin/phpunit --filter "tempnam_prefix_length|tempnam_invalid_dir|tempnam_null_byte|tempnam_jit" — OK (10 tests)

Implementation: PHP-in-PHP VmFsTempnam + thin mkstemp FFI; JIT/AOT via __compiler_tempnam (prefix normalize, NUL rejection, invalid-dir Notice + sys temp fallback). php-src refs: ext/standard/file.c, main/php_open_temporary_file.c.